Table 9.

Variability of HI and CR indices within the playgrounds under study

	Cd	Cr	Cu	Hg	Ni	Pb	Zn
	HI
Mean	0.0045	0.056	0.0003	0.0001	0.0005	0.0096	0.0002
Median	0.0041	0.055	0.0003	0.00005	0.0004	0.0080	0.0002
Max. value	0.008	0.15	0.001	0.001	0.001	0.04	0.0012
Standard deviation	0.0010	0.022	0.0002	0.0002	0.0002	0.0063	0.0002
Coefficient of variation	0.2314	0.396	0.5697	1.7511	0.3381	0.6524	0.7629
	CR
Mean	2 × 10−9	5.3 × 10−6	0	0	4 × 10−11	0	0
Median	1.3 × 10−9	3.1 × 10−6	0	0	2 × 10−11	0	0
Max. value	9.8 × 10−9	6.9 × 10−6	0	0	3.6 × 10−10	0	0
Standard deviation	1.5 × 10−9	8.9 × 10−6	0	0	5 × 10−11	0	0
Coefficient of variation	0.811	1.69	0	0	1.27	0	0